Questions 2.1

Questions to Chapter 2.1.1

{short description of image} Here are some raw questions
{short description of image} 1. Give examples and orders of magnitude for carrierr concentrations in various materials including the temperature dependence
{short description of image} Metals: k = 1....3 electrons per atom, n = k · density of atoms = k · (specific weight / atomic weight).
Examples for n = 1,2,3,.... (????)

n(T) independent of T; exception (semimetals, ...)
electrolytes (????)
graphite, ???
semicnductors
Superconductors
{short description of image} s and crystal lattice defects. What kind of defects would influence s? Most effecient defects?
{short description of image} Point defects, dislocations, grain boundaries, precipitations, second phases, ...
Point defects; l -argument.
{short description of image} T-dependence or Al resitance. Give graph.
Compare to rule of thumb
Resistivity of Al lines on ME circuits limits maximum length to l = 1 mm because R·C has to be kept below a certain value. Assuming that R and C are proportional to l; would it make (commercial) sense to replace the Al by a superconductor if length of 5 mm are required? Note: If a superconductor is used, the device needs to be cooled to < 100 K.
{short description of image} If theAl resistance decrease about 5 fold, it makes no sense
{short description of image} Figure of merit: High voltage cable, must withstand load of ... Own weight also important,..., price, resistivity,...
{short description of image} ????
{short description of image} Multiple choice questions
{short description of image} Chapter 2.1.1 Metals
  • Ohms law
  • Matthiesen rule
  • r(T) rule
  • Some numbers / order of magnitude for s
{short description of image} Chapter 2.1.2 Alloys
  • Immiscibility: Resitivity alloys < or > then constituents?
  • Nordheim rule
  • Graph for partial micibiliy gap: What happens for coplete immiscibility? for smalle range of ...?
  • Resisitivity intermetallic comiound, Why large than elements? (List of answers)
{short description of image} Chapter 2.1.3 Non-metallicCondctors
{short description of image} In addition: MC Questions from "Fischer" p. 155
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go to 2.3.1 Special Applications

go to Solution to 2.3.1